1. Field of the Invention
The present invention relates to a digital broadcast tuner and a digital broadcast receiver having the same, which are suitable for a digital television.
2. Description of the Related Art
FIG. 5 is a perspective view showing a known electronic circuit unit from which a portion has been cut out. FIG. 6 is a schematic plan view of a known digital broadcast receiver having digital broadcast tuners. The structure of the known electronic circuit unit will now be described with reference to FIG. 5. A rectangular circuit board 52 that has long sides and short sides is mounted within a square frame member 51 made of plate metal.
Various electronic components 53 are mounted on the circuit board 52 to form a desired electrical circuit. A plurality of terminals 54 are arranged in a line in proximity to one long side of the circuit board 52. The electrical circuit is connected to these terminals 54 to form a known electronic circuit unit. This arrangement is, for example, disclosed in Japanese Unexamined Patent Application Publication No. 2005-85863.
The known digital broadcast tuner that employs the above-described structure of the electronic circuit unit is shown in FIG. 6. An analog tuner circuit 55 and a digital signal decoder circuit 56 are formed on the circuit board 52. Pluralities of terminals 54 are arranged in proximity to one of the long sides of the circuit board 52 and consist of a first terminal group G1 that is electrically connected to the tuner circuit 55 and a second terminal group G2 that is electrically connected to the digital signal decoder circuit 56. Thus, the known digital broadcast tuner is formed.
The structure of a known broadcast receiver that employs the known digital broadcast tuner will now be described with reference to FIG. 6. A plurality of digital broadcast tuners are mounted on a motherboard 57 so that the long sides of the individual circuit boards 52 are opposed to each other and located a large distance from each other.
In addition, a plurality of MPEG signal decoder circuits 58 that are in a one-to-one correspondence with the respective digital broadcast tuners are formed on the motherboard 57. Each of the MPEG signal decoder circuits 58 is formed offset from one of the short sides of the circuit board 52 and near the second terminal group G2. The MPEG signal decoder circuit 58 and a portion of the second terminal group G2 are electrically connected through wiring lines 59. Thus, the known digital broadcast receiver is formed.
The known digital broadcast tuner, however, is disadvantageous in that pluralities of the terminals 54 are arranged in a line in proximity to the one of the long sides of the circuit board 52 and, therefore, the circuit board 52 becomes significantly long thereby becoming large and causing higher material cost.
Furthermore, the known digital broadcast receiver is disadvantageous in that each of the MPEG signal decoder circuits 58 is formed offset from the one of the short sides of the circuit board 52 in order to reduce the length of the connection lines with the second terminal group G2 and, therefore, the adjacent digital broadcast tuners require a large space therebetween. This makes the digital broadcast receiver large. In addition, the connection lines between the MPEG signal decoder circuit 58 and the second terminal group G2 is long, with a consequence of poor performance.